Monkey patch the node js bunyan logging

Question

Do you have an idea on how to monkey patch the node js bunyan methods like info, debug by using shimmer(https://www.npmjs.com/package/shimmer) ?

For example, this is my bunyan configuration:

let bunyanLog = require('bunyan')
let bunyanOpts = {
  name : "bunyan-logging",
  level : "debug"
}

let bunyanLogger = bunyanLog.createLogger(bunyanOpts)

So, in my app I can call

bunyanLogger.info('info message') // output: info message

I want to monkey patch this bunyanLogger.info() by adding another functionality. So when executing the bunyanLogger.info() we also send a Facebook/Slack notifications.

I could not find articles or tutorials in the net about monkey patching the bunyan. Thanks!